Brush gear for dynamo-electric machines



5, 1.932. c. A. PARSONS E1- AL 1,839,89

BRUSH GEAR FOR DYNAMO ELECTRIC MACHINES Filed March 19, 1929 2 Sheets-Sheet 1 I hyentovs m @zmww y B /fzlfiiiov ney W W Jan. 5, 1932. c. A. PARSONS ET AL BRUSH GEAR FOR DYNAMO ELECTRIC MACHINES Filed March 19, 1929 2 Sheets-Sheet 2 Patented Jan. 5, 1932 UNITED STATES PATENT OFFICE CHARLES ALGERNON 'I'ARSONSAND JESSEL' RO SEN, OF NEWCASTLE-ON-TYNE, ENG- LAND; SAID ROSEN ASSIGNOR TO SAID PARSONS; KATHARINE PAR-SONS, VINCENT THOMPSON, AND FREDERICK GORDON HAY BEDFORD LEGAL REPRESENTATIVES OF SAID CHARLES ALGERNON PARSONS, DECEASED 1 BRUSH GEAR FOR DYNAMO-ELECTRIC MACHINES Application filed March 19, 1929, Serial No. 348,157, and'in Great Britain April 20,1928.

The invention relates to brush gear for dynamo-electric machines, the object of the invention being to provide a construction of such brush gear which shall be simpler and 5 cheaper in construction and adjustment, and at the same time more efficient than brus gear constructions now in use.

In multi-polar dynamo-electric machines, the usual method of insulating the brush arms from the rocker necessitates many eX- pensive insulating joints and copper connections between the brush arms and the connecting rings, together with heavy copper connections to the main terminals, and the setting ofthe brush arms in correct alignment with the commutator segments is difiiinvention then be specifically pointed out in the claims.

Referring to the accompanying drawings, which are to a certain extent of a diagrammatic nature Figure 1 shows an elevation of a dynamo having a two-part commutator fitted with one form of brush gear in accordance with the present invention;

Figure 2 is a part end viewto a larger scale of the brush gear shown in Figure 1, v

Figure 3 being a cross-section through the rockers and adjacent parts on the line 33 of Figure 2; while finally Figure 4 shows a corresponding cross-section to a smaller scale of a modified form in which the rocker carrier is formed in halves insulated from each other.

In carrying the invention into effect acing a pair of radially-running brush arms,-

E and F, one arm on each side, on which are mounted the brushes, D, for the two parts of the commutator.

The rocker faces h, h, to which the brush arms E, E, are secured are in two aligned V series asshown, one ring carrying all the positive brushes and the other ring all the negative brushes, while the positive and negative brushes are arranged alternately as seen in end view, (see Figure 2).

The rocker carrier, L, of hollow annular form carries the rocker rings G, H, by help of insulated local facings, J, or, alternatively,

(see Figure a) the rocker carrier may be divided into two parts, L L separated circumferentially by insulation, U, inthe same way as the rocker and both insulated from earth.

a Any suitable means, such as T (Figure 2) also insulated, is provided for the adjustment of the rocker when the complete plant it in operation.

Preferably, each part of the gear described, for ease of assembly, is made in the usual manner in halves (see Figure 2) with a horizontal joint, K, the halves so formed being electrically connected.

If desired; each part of the brush rocker may be divided into arcuate lengths for ease in construction and assembly, while in some 3 cases a less number of such lengths than are required to complete the ring may be used. By virtue of the preferred form of theinvention, the following advantages are obtained in combination (a) A simple mechanical construction in which the parts are readily machined so that when assembling little or no adjustment of the brush arms is necessary;

(6) Separate insulation for each arm is eliminated;

brush (0) Connecting rings or leads usually of copper between all the positive and all the negative brush arms are not required;

((1) The rockers are further away than in usual constructi o ns from the commutator and there is consequently less danger of flashingover due for example to short circuits;

(0') The better DlGChflnlCill construction provides for a more effective method of in sulating the rockers and gives increased elec trical leakage surfaces;

The section of the rockers When of cast iron is sutiiciently largeto carrythecurrentto the terminals instead of using massive copper connections.

Various alterations can he made in the details of the gear above setforthjvitliout exceedingthc scope of the present invention.

hat is claimed is 1 1. in eombinatlon in brush gear iol' dy1'iamo -e lectrie n'zachines, a. carrier frame, a pair 01 ']Ll2iii\])0-il and insulated rockers movable on Siliit ."l'wme .and each "having .ln'acliet-like membei a which are .imbricated in relation to the bracket-like inenibers ot the other rocker, a pair ot' oppositelyextending brush-carrying arms associatedith each of said bracket-like members. to 'etlieiftvith posit ve brushes mounted on v those brush-carrying arms 2. sociated with the bracket-l ke members oi one of said juxtaposed rockers .and negati ve brushesmounted on the :ln'uslr carrying; arms associated with the bracketlilce members of the other of $EXlClJl1XtZ1PQ$GKl (rockers.

The combination of parts claimed in elenn l m which said C l 11161f1'21l116 is of ring-like form and divided circumferentially into two parts insulated from one another.

3. The combination of parts claimed claim 1, in which the bracket-like members are of channel section with alignedfacestor the accommodation of said brusl ca-rrying arms.

In testimony whereof We l'ravesigned our names to this specification.

CHARLES ALGERNON PARSONS. JESSEL :lOSEN. 

